public class MyCircularQueue {
    private int[] elem;
    private int front;
    private int rear;

    public MyCircularQueue(int k){
        this.elem = new int[k];
    }

    /**
     * 入队
     * 1.判断是不是满的
     * 2.把当前需要的存放的元素放到rear下标的地方
     * @param value
     * @return
     */
    public boolean enQueue(int value) {
        if(isFull()){
            return false;
        }
        elem[rear] = value;
        rear = (rear + 1) % elem.length;
        return true;
    }

    //出队
    public boolean deQueue() {
        if (isEmpty()) {
            return false;
        }
        front = (front + 1) % elem.length;
        return true;
    }

    public int Front() {
        if (isEmpty()) {
            return -1;
        }
        return elem[front];
    }
    //得到队尾元素
    public int Rear() {
        if (isEmpty()){
            return -1;
        }
         int index = (rear == 0) ? (elem.length - 1) : (rear - 1);
        return elem[index];
    }

    /**
     * 当前循环队列是否为空
     */
    public boolean isEmpty() {
        return rear == front;
    }

    /**
     * 判断当前队列是否为满
     * 浪费一个空间来表示满
     * @return
     */
    public boolean isFull() {
        if ((rear + 1) % elem.length == front){
            return true;
        }
        return false;
    }
}
